function_default_parameters.md

Default Parameters for Functions

For functions in JavaScript you can define a default value for a parameter for handling the case where a parameter is not provided, falling back to the dafault.

const greeting = (title = 'World') => {
    return `Hello, ${ title }!`;
};

console.log(greeting());

module.exports = { greeting }

So when greeting is invoced without any parameters like so: console.log(greeting()); it will emit the interpolated string:

$ node helloworld.js
Hello, World!

Resources and References

• Blog post by Dmitri Pavlutin: "Let's Master JavaScript Function Parameters"